PREX/CREX Mar 26, 2019 10:00am

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Logistic information

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Agenda

  1. Beam modulation: Victoria
    • VO: the old values for the modulation (X: 70uA, Y: 150uA current on coil) were from PREX1. We could probably have increased it even further.
    • VO: slide 5 is for 40 uA beam current
    • VO: the x modulation was much noisier so we are trying to make cuts so clean up the data.
    • SR: what was the range of motion for the energy coil? CG: the plot is of 14x but on 12x we should expect about 0.2mm amplitudes
    • VO: we need to fix the modulation pause, hopefully GM will help with that.
  2. Low current cavities: Ye[1]
    • YT: the internal gain factor for the cavity will need to be implemented in the GUI
    • YT: the bull’s eye scan was on Carbon (not W).
    • YT: the 4a showed some signal for 100nA but 4e was exactly 0
    • CG: is there an acceptance function for the scaler rates? YT: not clear
    • BM: striplings are not reliable under 0.5 uA. the 4A signal is kind of a miracle. We should clean up the data by looking at the steering coils currents.
  3. Compton: Amali hapLog3687
    • AP: the simulations had a 3.5% AN. The 70% polarization value is lower than expected (~82%)
    • KP: can you overlay the expected distribution over amplitude from the simulation? AP: will do.
    • AP: the expected Compton rate at 2uA was 2kHz. AP: the background was down to 70Hz/uA
    • KP: were the background linear from 2 to 20? DG: not linear, it went up by a factor of 1.5.
    • DG: the big spike at low amplitude in the spectrum was probably due to some activation. The detector counted even with beam off. JCC: the finger scintillators were also counting.
    • KP: there could be a pedestal error on the integration (potential problem extraction)
    • PS: is the detector integrating over more than one window? KP: we should be able to look at the trigger of the compton and change it independent of the helicity windows
  4. Moller: Sanghwa [2]
    • SP: the results are preliminary and we are actively investigating the data.
    • SP: we are investigating the reproducibility of the data. Effects from position/energy variations are prime suspects
  5. Discussion for next week:
    • Documentation: Bob
    • Beam line instrumentation: Caryn

Present

In F345

Cameron C, Tao Y, Ye T, Amali P, Caryn P, Ciprian G, Dave G, Sanghwa P, Robert R

Online

Bob M, David M, Kent P, Jinlong Z, Juan Carlos C, Seamus R, Victoria O, Silviu D, Devi A, Paul K, Paul S, Ryan R, Dustin M, Juliette M, Eric K, Siyu J, Bill H, Richard H, Chandan G, Guido U

Cannot make it

KK